import java.util.Date;

public class Main {
    public static void main(String[] args) {
        new User("张三");
        for (int i = 0; i < 100; i++) {
            System.out.println(new Date());
        }
    }

    public User getUser(){
        User user = new User("sans");
        // ...
        return user;
    }

    public void valid(User user){
        if (user != null) {

        }
    }
}
